1. Field of the Invention
The present invention relates to a recording paper exhibiting excellent performance as a toner-receiving paper in electrophotographic recording, and an electrophotographic image-forming method employing the recording paper.
The present invention also relates to a recording paper capable of forming sharp images in ink-jet recording, and an ink-jet image-forming method employing the recording paper.
2. Related Background Art
Electrophotographic copying machine, as an example, electrify a photoconductive sensitive member temporarily with an electrifier, form an electrostatic latent image, developing the latent image with a toner of a one-component type or a two-component type; transfer the toner on the sensitive member by a transfer-electrifier onto a recording paper delivered thereto, and fix the toner onto the recording paper by heat and/or pressure by means of a fixing roller, or the like, to obtain a final copied image.
The toner-receiving papers for use in such a copying machine are required to have properties as follows: (1) suitable electric resistivity and smoothness of the surface for satisfactory toner transfer, (2) high toner fixability, (3) less formation of paper dust, causing fewer image defects by adhesion of the formed paper dust onto a photosensitive member or an electrifying roller, (4) causing less abrasion of the photosensitive member, paper-delivering roller, or fixing roller by formed paper dust (e.g., a filler), (5) less occurrence of curling by heat, (6) less change of dimension due to humidity change, (7) high deliverability with low rigidity and an appropriate surface friction coefficient, and so forth.
Ink-jet recording is attracting attention because of its suitableness for high speed printing, color image recording, and high density recording, and the apparatuses for ink-jet recording are widely used. For ink-jet recording, specially designed papers are used, which are exemplified by a coated ink-jet paper disclosed in Japanese Patent Laid-Open Application No. 59-35977. On the other hand, in single color recording and business color recording, an ink-jet recording method is demanded which is suitable for recording onto inexpensive plain paper for general office use.
However, for electrophotographic recording, toner-receiving papers widely used in offices are not suitable for ink-jet recording, because of the disadvantages of: (1) insufficient ink fixing property, (2) insufficient water-fastness of the recorded images formed thereon with an aqueous ink, (3) insufficient color developing property for the coloring matter of the ink, and insufficient image density of the formed image, (4) occurrence of the feathering and bleeding of ink, resulting in low quality of the recorded images, and so forth.
For improving the water-fastness of the recorded images, Japanese Patent Laid-Open Application No. 61-58788 discloses recording paper which contains a polyallylamine salt. However, the recording paper containing a polyallylamine salt without a special coating layer has disadvantages that the formed image has a low density, and tends to cause bleeding.
For improving the ink fixing property, both the recording medium and the ink are investigated. The ink-recording medium is investigated for lowering the sizing degree of the recording medium itself to improve ink penetration, and wetting property. The ink is investigated for lowering the surface tension to improve wetting property and penetrability into the recording medium.
Any of the above improvements causes other problems, namely, cockling of the recording paper due to a large amount of penetration of the ink, and curling of the recording paper after ink drying.